mccp
I can't see any reason why you wouldn't be able to buy the factory extended warranty - it is still on the VW Commercial website after all. https://www.volkswagen-vans.co.uk/en/service-accessories/warranties/extended-warranty.html.
The brochure that you can download is pretty slim. I've attached the PDF that I got from my dealer last November. If your dealer doesn't think that it's available, buy it elsewhere - any VW Commercial dealer should be able to sell it to you within three months of your vehicle's registration date, although they only get £40 for a two year extension (see the PDF), so it's not that lucrative for them.
The brochure that you can download is pretty slim. I've attached the PDF that I got from my dealer last November. If your dealer doesn't think that it's available, buy it elsewhere - any VW Commercial dealer should be able to sell it to you within three months of your vehicle's registration date, although they only get £40 for a two year extension (see the PDF), so it's not that lucrative for them.